There are three heads to this beard, as I said. They are the unknowable head, Keter and concealed Chochmah. They extend and are all attached to this Mazala and remain in it. For this reason, the most precious comes down from this Mazala.
All the letters in the name Yud Hei Vav Hei that derive from this Atika (as said in section 53) all derive only from this beard. They are attached to this Mazala and depend on it to sustain the other letters that are in Zeir Anpin (as said in section 53). Letters are vessels and aspects of judgments. Judgments have no hold on Atika itself; but for the sake of preparing through them to sustain the lower beings, a unique Partzuf of hair was formed that derives from it (as explained at length in section 58; study there).
Had those letters not ascended to Atik, that is, to its beard, the other ones in Zeir Anpin would not have subsisted. Therefore, Moshe said in times of need, “Hashem, Hashem” twice. The first depends on Arich Anpin and the second on Zeir Anpin. There is a cantillation mark to separate them.
And all depend on Mazala instead of on Arich Anpin, as said. The higher beings are ashamed before this Mazala and the lower beings are subdued before it as said above (in the Greater Gathering, section 99; study there). Happy is the portion of he who attained that.